The two main weather features during the middle of this week include a Four Corners Low impacting the Southern Rockies and a trough of low pressure just off the BC/Washington Coast that will bring more wet weather to the Pacific Northwest.

A cold front sweeping across the West is resulting in noticeably cooler temperatures for most areas during the middle of the week. Below-average temperatures will prevail over the Four Corners region throughout the next 5 days, while the remainder of the West will see a warming trend later this week.

Taking a closer snapshot at Wednesday, our forecast radar projects widespread showers and thunderstorms across the Colorado mountains on Wednesday afternoon, and this will include high elevation snow.

Showers and wet conditions can also be expected throughout the day across Western Washington and Northwest Oregon, mainly along and west of the Cascade Crest.

Current Radar

Lightning Density

Forecast Radar

Forecast for Wednesday, September 29th

Precipitation on Wednesday will favor Western Washington as well as the Four Corners region, and a little bit into Southern Wyoming as well. California, Southern Oregon, Northern Utah, and the Northern Rockies will largely miss out on these storms.

Snow will fall across the higher elevations of Colorado, Northeast Utah, Northern New Mexico, and Southern Wyoming on Wednesday and Wednesday night. Accumulating snow could extend northward into the Southern Wind River Range as well. 

Forecast for Thursday, September 30th

The focus of precipitation will shift southward into Southern Colorado, New Mexico, and Eastern Arizona with decreasing showers farther north. Rain will continue across the Pacific Northwest with light showers reaching Eastern Washington/Oregon and Northern Idaho.

Snowfall on Thursday will favor the San Juan Range in Colorado and the higher peaks of Northern New Mexico. 

Forecast for Friday, October 1st

The Four Corners low will continue to impact Colorado and New Mexico on Friday with shower activity extending a little bit northward again (low elevation rain and high elevation snow). A weakening Northwest storm will bring a round of showers to Northern Idaho and Western Montana, while the Cascades and PNW Coast will see dry weather return.

Forecast for Saturday, October 2nd

There is some uncertainty as to the position of the Four Corners low on Saturday and resulting shower chances on Saturday. At this time, most mountain ranges in Colorado will have at least a chance of showers, though perhaps lighter compared to prior days. 

Forecast for Sunday, October 3rd

Showers will remain possible over Colorado and New Mexico with generally dry conditions expected elsewhere.

Outlook for Mon Oct 4th - Fri Oct 8th

Much of the west will see warmer temperatures next week, but an unsettled pattern will remain over the Four Corners region with additional showers possible, at least early in the week. The Northwest will start out mild and dry but will see increasing rain chances as a cold trough of low-pressure approaches late in the week.

The Four Corners region will see the best chance of showers during this period but should see a drying trend by late in the week. On the other hand, the PNW will start dry but will see increasing rain chances by the end of the week.

Thanks so much for reading! Next update on Friday (10/1).

ALAN SMITH

We will continue to post the Western U.S. Daily Summit 3x/week through Friday, October 1st.

Starting on Monday, October 4th, we will transition to the US & Canada Daily Snow, at which point we will still talk about impactful weather in the West as needed, but with more of a focus toward snow across North America as a whole as we change seasons.